Moylan, however, proved incompetent, and Mifflin resumed the office on the 1st of October.
In the autumn of 1 777 Mifflin was a leader in the obscure movement known as the Conway Cabal, the object of which was to replace Washington by General Horatio Gates.
On the ground of ill health Mifflin tendered his resignation on the 8th of October, and on the 7th of November Congress accepted his resignation as quartermaster general, but continued him in rank as major-general without pay.
The attacks on Washington failed, and in March 1778 Mifflin was finally superseded as quartermaster-general by General Nathanael Greene.
Merrill, Memoranda relating to the Mifflin Family (Philadelphia, 1890).